more fixes for Workspace

lib/ace/undomanager.js

@@ -1,4 +1,5 @@
-/* ***** BEGIN LICENSE BLOCK *****
+/* vim:ts=4:sts=4:sw=4:
+ * ***** BEGIN LICENSE BLOCK *****
  * Version: MPL 1.1/GPL 2.0/LGPL 2.1
  *
  * The contents of this file are subject to the Mozilla Public License Version
@@ -20,6 +21,7 @@
  *
  * Contributor(s):
  *      Fabian Jakobs <fabian AT ajax DOT org>
+ *      Mihai Sucan <mihai DOT sucan AT gmail DOT com>
  *
  * Alternatively, the contents of this file may be used under the terms of
  * either the GNU General Public License Version 2 or later (the "GPL"), or
@@ -70,6 +72,14 @@ var UndoManager = function() {
         this.$redoStack = [];
     };
 
+    this.hasUndo = function() {
+        return this.$undoStack.length > 0;
+    };
+
+    this.hasRedo = function() {
+        return this.$redoStack.length > 0;
+    };
+
 }).call(UndoManager.prototype);
 
 exports.UndoManager = UndoManager;